Move arm from ports to libc.

I've moved the ARM port from ports to the main sysdeps hierarchy.
Beyond the README update, the move of the files was simply

git mv ports/sysdeps/arm sysdeps/arm
git mv ports/sysdeps/unix/arm sysdeps/unix/arm
git mv ports/sysdeps/unix/sysv/linux/arm sysdeps/unix/sysv/linux/arm

and in addition to the ChangeLog entries here, I put a note at the top
of ports/ChangeLog.arm similar to that at the top of
ChangeLog.powerpc.  There is deliberately no NEWS change, as I think
it makes the most sense to put in a general note above all ports
having moved if we can achieve that for 2.20.

Tested that disassembly of installed shared libraries for arm is the
same before and after this patch, except for data (not instructions)
in ld.so (there are assertions in sysdeps/arm/dl-machine.h, and the
path by which that file is found, and so by which it appears in the
assertion message, changes as a result of the move).

	* sysdeps/arm: Move directory from ports/sysdeps/arm.
	* sysdeps/unix/arm: Move directory from ports/sysdeps/unix/arm.
	* sysdeps/unix/sysv/linux/arm: Move directory from
	ports/sysdeps/unix/sysv/linux/arm.
	* README: Update listing for arm-*-linux-gnueabi.

ports/ChangeLog.arm:
	* sysdeps/arm: Move directory to ../sysdeps/arm.
	* sysdeps/unix/arm: Move directory to ../sysdeps.arm.
	* sysdeps/unix/sysv/linux/arm: Move directory to
	../sysdeps/unix/sysv/linux/arm.

1 files changed, 79 insertions, 0 deletions

diff --git a/sysdeps/arm/find_exidx.c b/sysdeps/arm/find_exidx.c
new file mode 100644
index 0000000000..39910ed350
--- /dev/null
+++ b/sysdeps/arm/find_exidx.c
@@ -0,0 +1,79 @@
+/* Copyright (C) 2005-2014 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library.  If not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <link.h>
+#include <unwind.h>
+
+struct unw_eh_callback_data
+{
+  _Unwind_Ptr pc;
+  _Unwind_Ptr exidx_start;
+  int exidx_len;
+};
+
+
+/* Callback to determins if the PC lies within an object, and remember the
+   location of the exception index table if it does.  */
+
+static int
+find_exidx_callback (struct dl_phdr_info * info, size_t size, void * ptr)
+{
+  struct unw_eh_callback_data * data;
+  const ElfW(Phdr) *phdr;
+  int i;
+  int match;
+  _Unwind_Ptr load_base;
+
+  data = (struct unw_eh_callback_data *) ptr;
+  load_base = info->dlpi_addr;
+  phdr = info->dlpi_phdr;
+
+  match = 0;
+  for (i = info->dlpi_phnum; i > 0; i--, phdr++)
+    {
+      if (phdr->p_type == PT_LOAD)
+        {
+          _Unwind_Ptr vaddr = phdr->p_vaddr + load_base;
+          if (data->pc >= vaddr && data->pc < vaddr + phdr->p_memsz)
+            match = 1;
+        }
+      else if (phdr->p_type == PT_ARM_EXIDX)
+	{
+	  data->exidx_start = (_Unwind_Ptr) (phdr->p_vaddr + load_base);
+	  data->exidx_len = phdr->p_memsz;
+	}
+    }
+
+  return match;
+}
+
+
+/* Find the exception index table containing PC.  */
+
+_Unwind_Ptr
+__gnu_Unwind_Find_exidx (_Unwind_Ptr pc, int * pcount)
+{
+  struct unw_eh_callback_data data;
+
+  data.pc = pc;
+  data.exidx_start = 0;
+  if (__dl_iterate_phdr (find_exidx_callback, &data) <= 0)
+    return 0;
+
+  *pcount = data.exidx_len / 8;
+  return data.exidx_start;
+}